list error

[recluse]

i have just tried to implement a simple linked list to store a name such as "ben", however it compiles but doesnt print out the values, here is my code:

#include <stdio.h>

typedef char DATA;

struct linked_list{
    DATA d;
    struct linked_list *next;
};

typedef struct linked_list ELEMENT;
typedef ELEMENT* LINK;

LINK string_to_list(char s[])
{
    LINK head;
    
        if( s[0]=='\0')
        return NULL;
    else{
        head=malloc(sizeof(ELEMENT));
        head->d=s[0];
        head->next=string_to_list(s+1);
        return head;
    }
}

int main(void)
{
    char *s;
    LINK head=NULL;
    LINK tail=NULL;
    LINK next;
    char a;
    scanf("%s", string_to_list(&s));
     for( ; head ; head = next ) {
    printf( "%c", head->d );
    next = head->next;
    free( head );
    }
    return 0;
}

where have i gone wrong?

[Salem]

> scanf("%s", string_to_list(&s));
I'm pretty sure this doesn't compile - your compiler is broken if it does.
1. read input into a separate string
2. assign the return result of this function to head

[recluse]

it does compile, but with warnings... then it crashes

here is my code now:

 #include <stdio.h>

typedef char DATA;

struct linked_list{
    DATA d;
    struct linked_list *next;
};

typedef struct linked_list ELEMENT;
typedef ELEMENT* LINK;

LINK string_to_list(char s[])
{
    LINK head;
    
        if( s[0]=='\0')
        return NULL;
    else{
        head=malloc(sizeof(ELEMENT));
        head->d=s[0];
        head->next=string_to_list(s+1);
        return head;
    }
}

int main(void)
{
    
	char *b;
    LINK head=NULL;
    LINK tail=NULL;
    LINK next;
     scanf("%s", b);
	string_to_list(b);
     for( ; head ; head = next ) {
    printf( "%c", head->d );
    next = head->next;
    free( head );
    }
    return head;
}

are there any tutorials for more advanced list topics such as reversing them and deleting elements in a list? i can only seem to find simple ones on the concept of lists.

[Salem]

Are you even paying the slightest bit of attention?

> char *b;
Where does this point?
Answer - nowhere, so where do you think scanf("%s", b); is going to write all your input?

> string_to_list(b);
I said "2. assign the return result of this function to head"
How far do you think your for loop will get without this assignment?

> return head;
main returns an int

> it does compile, but with warnings
I should hope so - perhaps you should focus on addressing those before trying to run the code.
Newbies have no business running code which contains warnings.


Oh, and include stdlib.h